1. Field of Invention
This invention relates generally to mobile radiotelephones useable in cellular telephone systems, and more particularly to a miniature radiotelephone set borne on the wrist of its user.
2. Status of Prior Art
A conventional telephone hand set which is connected to a telephone line includes a generally rectangular case having at one end a mouthpiece housing a microphone and at its other end an earpiece housing an earphone or speaker. To use this set, a user grasping the case in his hand raises the set to place the earpiece against his ear and the mouthpiece adjacent his mouth. Hence with a conventional telephone set it is the shape of the case and its dimensions which act to properly orient the microphone and earphone with respect to the mouth and ear of the user.
A cellular telephone set is a mobile radiotelephone that operates in conjunction with a network of short range microwave transmitters located in overlapping cells throughout a region, calls from a radiotelephone set being switched from one transmitter to the next as the caller enters an adjoining cell. A central station switches the calls and makes connections to regular telephone lines.
A cellular telephone set is constituted by a self-sufficient battery-powered microwave radiotelephone that is usually carried by the user on his person. Hence a cellular telephone set is often in a foldable format to render it more compact when not in use. But whatever its format, a cellular telephone set is provided with a case supporting a mouthpiece at one end and an earpiece at the other, these being spaced apart by the case so that when the case is raised by the user, the earpiece is against the ear of the user and the mouthpiece is then near his mouth.
Thus in a conventional wireless cellular telephone set as in a conventional wired telephone set, it is the case that functions to support the mouthpiece and the earpiece and to space the microphone from the earphone and thereby properly orient these components with respect to the mouth and ear of the user.
The 1989 patent to Olsen U.S. Pat. No. 4,847,818 discloses a wrist-watch radiotelephone useable in a cellular system in which a miniature transceiver is housed in a case strapped onto a wrist of the user. The two piece strap has a pair of strap ends adapted to be connected together for holding the case on the user""s wrist. Attached to one strap end is a mouthpiece containing a microphone connected to the input of the transceiver, while attached to the other strap end is an earpiece containing an earphone connected to the transceiver output.
In order to make or receive a call, the user of the Olsen radiotelephone must detach the cased transceiver from his wrist, straighten out the pair of straps and grasp the case and raise it to place the microphone at one strap end adjacent the mouth and to place the earphone at the other strap end against the ear.
While Olsen""s wrist-borne radiotelephone obviates the need to carry a much larger mobile radiotelephone set, it has a serious drawback, for each time a call comes in or is to be made, the user must unstrap the radiotelephone from his wrist, and when the call is completed, he must restrap the set on his wrist. The wrist-borne radiotelephone shown in the 1993 patent to Houlihan U.S. Pat. No. 5,260,915 suffers from the same drawback, for to use this radiotelephone it must be taken off the wrist.
Also showing a wrist-borne radiotelephone in a watch format is the 1991 U.S. Pat. No. 5,008,864 to Yoshitake in which the microphone and earphone are mounted on the strap. Hence to use this radiotelephone it must be unstrapped from the wrist.
To provide a wrist-borne radiotelephone set that need not be unstrapped from the wrist in order to be put to use, the 1995 Blonder et al. U.S. Pat. Nos. 5,381,387 discloses an arrangement in which the radiotelephone is secured to the wrist by a strap that encircles the wrist, this wrist strap having a lateral strap extension that extends into the palm of the hand. A microphone is mounted at the junction of the wrist strap and the strap extension, while an earphone is placed at the end of the strap extension so that it lies in the palm of the hand.
In operating the Blonder et al. radiotelephone, the user raises his arm so that his hand is cupped over one ear to bring the earphone next to the ear, the microphone then being proximate to the user""s mouth. Similar arrangements are shown in the Blonder et al. U.S. Pat. Nos. 5,499,492 and 5,239,521.
A disadvantage of Blonder et al. wrist-borne radiotelephone sets is that the strap extension carrying the earphone sticks out as an appendage from the strap encircling the wrist. This appendage is subject to being struck and damaged as the user manipulates his arm.
Of greater prior art interest is the 1995 patent to Houlihan U.S. Pat. No. 5,467,324 which provides a wrist-borne radiotelephone set that does not have to be taken off the wrist to be put to use and which has no appendage attached to its strap. In Houlihan, the microphone is mounted on the case housing the transceiver, whereas the earphone is connected to the transceiver by a retractable cable that is pulled out of a reel housed in the case strapped onto the wrist of the user. Hence to use this radiotelephone, the user raises one hand to place the microphone next to his mouth and pulls out the earphone to place the earphone adjacent his ear.
In view of the foregoing, the main object of this invention is to provide a miniature radiotelephone set useable in a cellular telephone system that it strapped onto the wrist of a user""s hand and is operable to send out voice messages and to receive incoming voice messages without having to unstrap the set from the wrist to do so.
More particularly, an object of this invention is to provide a set of the above type that includes a microphone and earphone in an arrangement in which the hand of the user and a finger thereon serve to properly orient the microphone and earphone with respect to the mouth and ear of the user.
Among the significant advantages of a wrist-borne radiotelephone set in accordance with the invention are the following:
A. The set is dimensionally not much larger than a standard men""s wrist watch, yet functions effectively as a much larger conventional cellular telephone set.
B. The wrist-borne radiotelephone set has no appendages; hence when the user who has the set strapped onto his wrist manipulates his arm, in doing so he will cause no injury to the appendage-free set strapped to his wrist.
C. The wrist-borne radiotelephone set, when a call is received or is to be made, can then be quickly put into an operative mode, for all the user need do is to insert a finger of his hand in a thimble carrying the earphone and raise his hand to insert the thimble in one ear, this action placing the earphone into the ear and at the same time placing a microphone mounted on the strap adjacent the mouth of the user.
D. The antenna for the transceiver is incorporated in a retractable cable connecting the earphone to the transceiver output. Hence when the transceiver is put to use by pulling out the cable to place the earphone against the ear, the antenna is then fully extended.
Briefly stated these objects are attained by a radiotelephone set in which a case housing a miniature microwave transceiver is strapped to the wrist of a user""s hand, a microphone mounted on the strap being connected to the transceiver input whereby when the hand is raised to bring the microphone adjacent the user, the user can then transmit voice messages. An earphone placed within a finger thimble is connected by a cable normally retracted within the case to the transceiver output to reproduce messages received by the transceiver.
To operate the radiotelephone set, the thimble carrying the microphone is pulled away from the case to extend the cable, the thimble being then mounted on the index finger of the hand. The hand is then raised so that the thimble can be inserted by the index finger into an ear of the user who can now hear incoming voice messages. When so raised, the hand acts to place the microphone on the strap adjacent the mouth of the user who can now send out voice messages. Thus the hand of the user and a finger thereon together function to properly orient the microphone and earphone of the set with respect to the mouth and ear of the user.